The Antigua and Barbuda international moved to the City Ground from QPR in the 2009-10 season and bagged an impressive 14 goals.

However, the 26-year-old Oxford-born forward, who is in the final year of his contract, recently questioned how Forest would be able to challenge for promotion unless manager Steve Cotterill is backed heavily by the club's hierarchy.

Scottish Premier League champions Celtic are looking to strengthen their squad in time for the start of the new campaign and have made a verbal offer for Blackstock.

Manager Neil Lennon is aiming to qualify for the UEFA Champions League group stage for the first time since 2008/09.

Meanwhile, Cotterill could look to take advantage of the loan market again next season after the likes of Adlene Guedioura, George Elokobi, Scott Wootton, Greg Cunningham and Danny Higginbotham helped successfully keep Forest in the Championship.

"I would not rule out bringing in a few players on a season-long loan basis, I think that can work well if you have the right player," said Cotterill.

"And we have used the loan market well in the past. But it has to be the right player, there is no point in signing just anyone for the sake of it."